The present invention provides a method of sterilizing musical wind instruments. More particularly, the present invention provides a sterilization method using a gas diffusion process and a gas sterilant, such as ethylene oxide, to sterilize, or at least sanitize, musical wind instruments that are shared by two or more persons.
Playing musical instruments is a very popular activity in the United States and throughout the world. Musical instruments generally fall into three classes: string instruments, percussion instruments and wind instruments. The string instruments, i.e. violins, guitars, cellos and the like, produce musical tones by bowing or plucking strings which vibrate in audible frequencies. The percussion instruments, i.e. drums, gongs, cymbals, tympani and the like, produce sounds by providing a surface which is struck with a stick, mallet or similar object. One hybrid instrument, the piano, produces tones using strings which are struck by padded hammers that are controlled using a keyboard. Finally, the wind instruments produce musical tones when air is blown through them or across openings in them.
The wind instruments are classifying in two main categories. Brass instruments, such as trumpets, French horns, trombones, tubas and the like, are usually constructed of metals and include a bell shaped mouthpiece that the musician places against his or her lips. Woodwinds, such as clarinets, saxophones, oboes, bassoons and the like are usually constructed of a variety of materials and include a single or double reed which is placed partially in the musician""s mouth. One family of woodwinds, the flutes, do not include a reed, but rather have an aperture called an embouchure which the musician blows across to produce a musical tone.
A wide variety of materials is employed in constructing wind instruments. While the brass instruments are constructed primarily of metals, woodwinds tend to comprise a combination of woods, metals, plastics, rubbers and fibrous materials such as cotton. In fact, some flutes even use fish scales in the design of pads which cover and expose various keyholes. Since the wind instruments are played by blowing into them, it is natural that some of the musician""s body fluids, including blood elements, saliva and water vapor, will accumulate in their interiors. Instruments that include curved portions often include a mechanism, called a spit-valve, that can be opened to allow accumulated fluids to be drained from the instrument.
Most serious musicians own their instruments and treat them as very personal objects. That notwithstanding, however, many beginning music students, particularly those in elementary and secondary schools, use instruments which they have borrowed from the institution in which they receive their musical training. Typically, a student may rent an instrument for a semester or a school year, returning it upon completion of the rental period. In many locations, the practice is to store the returned instrument until the next musician seeking such an instrument rents it. There is nothing to guarantee that each student will receive the same instrument from rental term to rental term.
As a result of these practices, student musicians often obtain instruments that have been rented and used by others. This raises sanitary issues, however, because at present, little if anything is done to clean or sanitize instruments between rentals. Thus, while the exterior of the instruments may receive a polish, the interior remains coated with dried saliva and exhaled water vapor from the prior user. This raises potential problems since the interior of wind instruments, particularly when damp, can form an excellent environment for the growth of infectious microbes, such as bacteria or viruses, which can cause illness when ingested or inhaled. The medical model of universal precautions mandates that all patients and the devices used in their treatment (especially when bodily fluid contamination is included) be viewed as potentially infectious. Applying these precautions to musical wind instruments makes good sense, since musical wind instruments, and particularly their interiors, are repeatedly contacted with bodily fluids as a natural result of the musician playing the instrument.
Sterilization of instruments raises several difficult practical and technical problems. For example, on the practical side, any sterilization must be relatively affordable, simple and not overly time-consuming. On the technical side, the sterilization of items constructed of a variety of materials including organic materials such as woods and cotton is a challenge. Of course, any sterilization method employed must be one which causes virtually no physical damage to the instrument. This is an issue because many known sterilizing agents, such as ultraviolet radiation, are known to degrade organic materials such as wood.
Thus, a need exists for affordable and efficient methods which allow the sterilization, or at the very least, the sanitization, of musical wind instruments. These methods must also be such that they do not damage the musical wind instruments during the sterilization process.
The invention provides a method of sterilizing a musical wind instrument using a gas diffusion process. In a first embodiment of the invention, the method of sterilization comprises steps of placing the musical instrument in an open, sealable diffusion bag, evacuating air from the diffusion bag, sealing the diffusion bag to achieve a leak-proof seal, placing the diffusion bag in a chamber of a sterilizer equipped with an exhaust ventilation system, creating a sterilizing atmosphere within the diffusion bag by introducing a gas sterilant, such as ethylene oxide or propylene oxide, into the interior of the diffusion bag, heating the gas sterilant to an appropriate temperature, maintaining the temperature of the gas sterilant for a sufficient time to achieve sterilization, or at least sanitization, of the musical wind instrument, and removing the diffusion bag from the sterilizer with the musical wind instrument contained therein.
In a version of the first embodiment, the sterilizing atmosphere is created within the interior of the gas diffusion bag by introducing a unit dose of ethylene oxide into the interior of the diffusion bag by a remotely-activated cartridge that releases 100% ethylene oxide gas, at a concentration of about 600 mg/l to about 750 mg/l, into the diffusion bag upon activation by an external trigger. The unit dose of ethylene oxide is measured in relation to a volume of the interior of the gas diffusion bag. The ethylene oxide gas is heated to an appropriate sterilization temperature of about 45xc2x0 C. to about 55xc2x0 C., and maintained at such temperature for a sufficient time of about 4 to about 16 hours to achieve sterilization. After completion of sterilization, residual ethylene oxide gas molecules absorbed by gas-absorbent materials of the musical wind instrument and contained within the diffusion bag and the sterilization chamber are substantially removed by purging and exhausting ethylene oxide gas molecules for a sufficient time of about 16 to 24 hours to the outside atmosphere.
The gas diffusion bag is constructed of a suitable material that is tear-resistant and allows ethylene oxide to diffuse outwardly from the interior of the diffusion bag, such as, although not limited to, low density polyethylene.
In a second embodiment of the invention, the ethylene oxide gas is introduced into the interior of the gas diffusion bag to create the sterilizing atmosphere by a gas cylinder injector system. The gas cylinder injector system contains a gas cylinder containing 100% ethylene oxide and is equipped with an adjustably connected injector. The injector is inserted into the gas diffusion bag, withdraws or evacuates air from the diffusion bag, and injects ethylene oxide gas into the gas diffusion bag. The gas diffusion bag is then sealed to achieve a leak-proof seal. The injection of ethylene oxide into individual the gas diffusion bag proceeds within operation of a high-volume exhaust ventilation system that exhausts diffusing gas molecules to the outside atmospheres. The gas diffusion bag is thereafter placed either in the sterilization chamber of the sterilizer or into a temperature-controlled chamber or room. The gas cylinder injector system is conducive for use with multiple lots of individual gas diffusion bags.
In a third embodiment of the invention, the musical wind instrument is contained in a musical instrument carrying case and placed within the interior of the gas diffusion bag for sterilization. During the sterilization process, ethylene oxide gas molecules diffuse through the instrument carrying case and contact the musical wind instrument contained therein.
In a fourth embodiment of the invention, the sterilizing atmosphere is provided by a standard ethylene oxide sterilizer, such as an ethylene oxide sterilizer used by hospitals to sterilize medical instruments, wherein the gas diffusion bag is placed within the sterilization chamber of the ethylene oxide sterilizer and ethylene oxide is released into the sterilization chamber. Upon heating ethylene oxide to an appropriate temperature, ethylene oxide gas molecules diffuse through a polyethylene member incorporated with a wall of the gas diffusion bag. Ethylene oxide gas molecules circulate throughout the gas diffusion bag, contacting the musical wind instrument contained therein.